An Unbiased View of a-BBO Crystal
An Unbiased View of a-BBO Crystal
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The length of your SHG crystal drastically affects the spectral width in the reference pulse, or alternatively the bandwidth from the SHG filter.
While this guideline gives a standard trend, It's not a quantitative Examination of LIDT vs wavelength. In CW programs, As an example, injury scales much more strongly with absorption from the coating and substrate, which isn't going to necessarily scale well with wavelength.
This efficiency is vital, particularly when a person considers the era in the 266nm wavelength, where even insignificant inefficiencies may result in major Electrical power losses.
Numerous factors can affect the effectiveness of BBO crystals. These consist of temperature, humidity, and the caliber of the incident mild. Suitable dealing with and storage will help maintain the crystal’s performance. Temperature can impact the period-matching circumstances of BBO crystals, which subsequently influences their efficiency in frequency conversion applications.
). This spatial focusing constraint about the SHG system will typically bring about the crystal duration often remaining lower than the Rayleigh number of the input focused pulse.
Stage matching significantly enhances the conversion efficiency and can be required to get hold of sufficient frequency-doubled mild for apps, but next harmonic technology (SHG) will manifest even if phase matching just isn't performed. The result of period matching to the output depth of SHG light-weight (I2ω) is illustrated in Determine sixteen.
When an optic is broken by a steady wave (CW) laser, it is frequently due to the melting with the surface due to absorbing the laser's energy or harm to the optical coating (antireflection) [one]. Pulsed lasers with pulse lengths lengthier than one µs could be addressed as CW lasers for LIDT discussions.
Comprehension Crystal is akin to appreciating the bedrock of advanced optical technologies. At its essence, BBO, or Beta Barium Borate, stands as a nonlinear optical crystal. The term “nonlinear�?here signifies the exclusive means from the crystal to connect with gentle within a method that alters The sunshine’s frequency.
Nonetheless, there's no next order nonlinear influence in alpha-BBO crystal as a result of centrosymmetry in its crystal composition and thus it's no use for second buy nonlinear optical processes. As a substitute, alpha-BBO is extensively employed for fabrication of polarizers, polarizing beam displacers, section retarders, birefringent plates, and time delay compensators Specially those for UV and large ability lasers.
As will probably be mentioned below, You will find there's concentrating numerical aperture (NA) limitation for the SHG section-matching procedure particularly analogous to the spectral period matching limitation mentioned in the preceding section (
Future, the ability/Power is possibly improved or lowered as well as optic is exposed at ten new areas. This method is repeated right until injury is noticed. The harm threshold is then assigned being the highest electric power/Power which the optic can stand up to without triggering damage. A histogram including that beneath signifies the screening of one BB1-E02 mirror.
A advisable guideline for concentrating femtosecond laser pulses into a nonlinear crystal is to maintain a Rayleigh variety that is certainly no less than various periods lengthier compared to length more info in the SHG crystal. This minimizes the prospect of harming the crystal, and decreases the adverse consequences of spatial stage mismatch and spatial (Poynting vector) stroll-off.
Technology of deep ultraviolet radiation at 210 nm by Form-I 3rd harmonic era is reached in a pair of BBO crystals with conversion efficiency as high as 36%.